* Under the hood in the fuse box: This is the most common location. The fuse box is usually located near the battery, often on the driver's side fender well. Look for a diagram on the inside of the fuse box cover to identify the fuel pump relay.
* Under the dash: Less common, but possible on some models. Check fuse boxes under the dashboard, typically near the steering column. Again, consult the fuse box diagram.
To find it definitively:
1. Consult your owner's manual: This is the best resource. The manual will have a diagram showing the location of all relays and fuses.
2. Check the fuse box diagrams: Even without the manual, the inside cover of the under-hood and under-dash fuse boxes often have diagrams. Look for a symbol that represents a fuel pump or a relay specifically labeled as the "fuel pump relay."
3. Use a wiring diagram: A wiring diagram for your specific 1987 Chevrolet pickup (you'll need to know the engine size and trim level) will show you the exact location and routing of the fuel pump relay circuit. These diagrams can be found online (often for a fee) through automotive repair websites or manuals.
4. Use a multimeter: If you're comfortable with basic electrical testing, you can trace the fuel pump circuit from the pump itself back to the relay. This requires some electrical knowledge and safety precautions.
Without knowing the specific engine and trim of your truck, pinpointing the exact location is impossible. Using the steps above will greatly increase your chances of finding it.
